Day 1 M5: connecting to the internet

Question 1

silos of devices that connect to the internet:

Answer 1

desktop, laptops, servers, data centers, routers, switches, tablets, cell phones, ATM, industrial equipment, medical devices, cars.

Question 2

Physical layer

Answer 2

cabling

Question 3

data link layer

Answer 3

ethernet

Question 4

What is PSTN, or POTS?

Answer 4

The existing infrastructure of the public telephone network. Public Switched Telephone network, or PSTN. Plain Old Telephone Service.

Question 5

a system built using the POTS, or PSTN, the phone line to transmit data. A permanent precursor to dial-up networks. A form of this is still in use today.

Answer 5

Usenet

Question 6

uses POTS for data transfer. Gets its name because the connection is established by dialing a phone number. awful sound. May be the only option in some rural communities, even today. It used to be the main way computers communicated over long distances. We’d have to choose between using the phone or using the internet.

Answer 6

Dial-up connection

Question 7

How is transferring data across a dial up connection done?

Answer 7

through modems.

Question 8

modulator demodulator. They take data computers can understand and turn them into audible wavelengths that can be transmitted over POTS, similar to how line coding turns ones and zeroes into modulating electrical charges across ethernet cables.

Answer 8

What is a modem?

Question 9

baud rates of early modems

Answer 9

very low.

Question 10

A measurement of how many bits could be passed across a phone line in a second

Answer 10

baud rate

Question 11

Baud rate in 1950s

Answer 11

110 bits per second.

Question 12

Usenet development baud rate

Answer 12

300 bits per second

Question 13

baud rate by 1990s, when internet became commodity

Answer 13

14.4 kilo bits per second.

Question 14

Another term for POTS, or Plain old telephone service

Answer 14

Public switched telephone network

Question 15

a baud rate is a measurement of the number of

Answer 15

bits that can be sent across a telephone line every second.

Question 16

What system did Duke grads build that is still in use today?

Answer 16

Usenet

Question 17

what device is used to transfer data across a dial-up connection?

Answer 17

Modem

Question 18

Modems take data that computers can understand and turn them into ____ that can be transmitted over POTS

Answer 18

audible wavelengths

Question 19

any connectivity technology that isn’t dial-up internet. Almost always faster than even the fastest dial-up. Refers to connections that are always on. There are long-lasting connections that don’t need to be

Answer 19

Broadband defined in terms of internet connectivity

Question 20

what is faster, dial up or broadband

Answer 20

broadband

Question 21

Does broadband or dial-up have long-lasting connections that don’t need to be established with each use, and are always present? connections that are always on?

Answer 21

broadband

Question 22

What were T-carrier technologies invented to do?

Answer 22

transmit multiple phone calls over a single link.

Question 23

What was common in businesses by the 90’s?

Answer 23

Using T-carrier technologies.

Question 24

T-carrier technologies became

Answer 24

common transmission systems to transfer data faster than dial-up.

Question 25

image loading on dial-up

Answer 25

took many seconds to download and display

Question 26

a 2mb high res photo download speed on fastest dial up

Answer 26

20 minutes, with a baud rate of 14.4 kb per second, to download 16,777,216 bits.

Question 27

what wouldn’t we have so much transmission of without broadband?

Answer 27

Pictures and videos.

Question 28

What do T-carrier technologies require, which makes them expensive?

Answer 28

dedicated lines. You usually only see them in use by businesses.